Semi-Tube Slingshot

thingiverse

UPDATE! http://www.thingiverse.com/thing:1739306 Learn more about the story of the Semi-Tube Slingshot and its performance at www.slingshotforum.com. Search for 'aiping'! Features Fork cones are oval, allowing flat bands up to 9 cm wide to be attached. My favorite is a 9 cm / 3,5 cm / 25 cm TBB with an active band length of 24 cm and a draw of 130 cm. The draw weight is about 11 kg. Band life time is then max 30 shots, depending on the weight of the ammo. Two bands can simply be made from one strip TBB 12,5 x 26 cm by cutting diagonal from the two opposite 9 cm marks and equalizing the ends to a symmetric trapeze. A detailed procedure for band attachment can be found here: http://slingshotforum.com/topic/50425-semi-tube-slingshot-pouchband-attachment/. Tests with multilayer TBB (blue&black) showed that single layer TBS/TBG should be no problem. The steel ball dispenser is up to 13 mm, prepared to glue in a magnetic disk diameter 10 mm / height 5 mm. My favorite 9,5 steel has no or mild hand-slap. A tactical flashlight holder with a diameter of 14 mm is also included. Don't use a laser for aiming! The tilted fork supports a straight fist. Warning! This slingshot is only for experienced shooters who draw at least 5 times the effective band length. You need speed to let the ball exit before the semi-tubes expand and block the trajectory. Use of this slingshot is at your own risk, especially full butterfly! No bands longer than 28 cm, taper at least 2:1. LEGAL&SECURITY: Only print and use this slingshot according to the legal regulations of your country. NEVER EVER shoot at humans, even not point and aim. ALWAYS use protective glasses. I strongly suggest a catch box made at least from 15 mm plywood, 20 cm dense plastic foam or 1 mm steel. Don't shoot at concrete or brick walls due to violent ricochets, which can seriously injure yourself or bystanders, of course damage windows, flat screens etc. Only shoot as far as you are able to see, aim AND hit your target. Band attachment: Bands should be at least 5 cm wide at the fork, wrap symmetrically from the upper oval tip, wider bands up to 9 cm until it touches the inner fork then utilize the outer fork. The flat-band should overlap the groove about 5 mm. To fix the flat band, I use small office rubber that fits on the loop of my index finger/thumb. Don't cut the loop open. Wrap with strong force so that office rubber color becomes pale just before rupture. The bands don't snap off because the oval groove ensures an equal force distribution of the band fixing rubber and the fork cone also supports grip. Slingshot orientation: Ball dispenser AWAY from your body, touching the inner index finger. The flat bands are directed from the grove to the end of the fork cones. This version is for hold left and draw right handed. Print Settings Printer: daVinci 1.0 Rafts: Yes Supports: Yes Resolution: 0.3 ABS Infill: 30% is enough for me Notes: 20% infill reduces/absorbs a lot of the ricochet energy in case of a fork hit! If you have doubts about stability due to low infill or after a fork hit, put the slingshot on solid ground so that it forms a bridge and step on it. If it does not break from 60 up 90 kg its good for shooting. If you have really big hands, scale it up so that you feel comfortable with the grip.